Scientists studied what happens when pregnant mice are exposed to extra male hormones and then eat a high-fat diet. They found that these conditions affected not just the babies, but their grandchildren and great-grandchildren too. Female mice showed signs of a condition called PCOS (polycystic ovary syndrome) with trouble getting pregnant, while male mice had problems with sperm quality. Surprisingly, some effects changed across generations—sometimes getting better, sometimes worse. This research suggests that what happens during pregnancy and early life can have lasting effects on fertility that may even be passed down to future generations.
The Quick Take
- What they studied: How combining extra male hormones during pregnancy with a high-fat diet affects the ability to have babies, not just in the exposed animals but in their children and grandchildren too.
- Who participated: Laboratory mice (multiple generations: F0 mothers, F1 offspring, F2 grandchildren, and F3 great-grandchildren). The study compared mice exposed to male hormones and/or high-fat diet versus control mice.
- Key finding: Female mice exposed to both extra male hormones and high-fat diet had trouble getting pregnant and showed signs of PCOS. Male mice in the third generation showed reduced sperm quality and fertility problems. Some effects were passed down to future generations, even when those generations weren’t directly exposed.
- What it means for you: This research suggests that conditions during pregnancy and early diet may have long-lasting effects on reproductive health that could affect multiple generations. While this is animal research, it highlights the importance of healthy pregnancy conditions and diet. However, more research in humans is needed before making specific health recommendations.
The Research Details
Researchers started with pregnant mice and gave some of them extra male hormones (a substance called DHT) during specific days of pregnancy, while others received a placebo. After birth, the baby mice were split into groups—some ate a normal diet and others ate a high-fat diet. The researchers then tracked what happened to the babies (F1 generation), their children (F2 generation), and grandchildren (F3 generation), even though the later generations only ate normal food. They measured many things including when the female mice reached puberty, their ability to get pregnant, sperm quality in males, and various hormone and metabolic markers.
This approach allowed scientists to see which effects came directly from the prenatal hormones, which came from the high-fat diet, and which effects were inherited by future generations. By following three generations, they could track how these problems were passed down through families.
The study used a well-established mouse model of PCOS (a common condition affecting fertility in women) combined with dietary stress to see how these two factors together might affect reproduction across generations.
Understanding how conditions during pregnancy and early life affect not just one generation but multiple generations is important for public health. This research helps explain why some reproductive problems run in families and why diet and prenatal environment matter so much. The findings suggest that improving pregnancy conditions and diet could have benefits that extend far beyond just one person.
This is a controlled laboratory study, which means researchers could carefully control all variables and track multiple generations systematically. The study measured many different outcomes (physical development, fertility, hormones, metabolism) which strengthens the findings. However, because this is animal research in mice, the results may not directly apply to humans. The study appears to be well-designed with clear experimental groups and multiple generations tracked, which increases confidence in the results.
What the Results Show
Female mice exposed to extra male hormones during pregnancy showed clear signs of PCOS-like problems. They reached puberty later than normal, had physical changes that looked more masculine (like increased distance between certain body parts and enlarged clitoris), and had smaller uterus and breast development. Most importantly, they had trouble getting pregnant and had smaller litters. When these females also ate a high-fat diet, their problems got worse.
Interestingly, the female offspring of mice that ate the high-fat diet (F2 and F3 generations) actually reached puberty earlier and had larger litters than expected. This suggests the effects changed across generations in unexpected ways.
Male mice didn’t show major problems in the first generation, but by the third generation (great-grandchildren), males whose ancestors ate the high-fat diet had significantly reduced sperm quality, including lower sperm count and reduced sperm movement. These males also had trouble fathering offspring. They also showed changes in cholesterol and triglyceride levels and in a hormone called LEAP2.
The key finding is that some reproductive problems were inherited across generations, even when later generations weren’t directly exposed to the original triggers.
Beyond fertility problems, the study found changes in metabolic markers (cholesterol and triglycerides) in males of the third generation, suggesting that the high-fat diet affected not just reproduction but overall metabolic health. Changes in hormone levels (specifically LEAP2, which is involved in metabolism and appetite) were also detected. These findings suggest that the effects of prenatal hormones and diet extend beyond just reproductive organs to affect whole-body health.
Previous research has shown that PCOS can be modeled in animals using prenatal androgen exposure, and that high-fat diets harm fertility. This study is novel because it combines both factors and tracks effects across three generations. The finding that effects are inherited across generations aligns with emerging research in epigenetics—the idea that environmental factors can affect how genes are expressed and that these changes can be passed down. However, the specific patterns found here (some effects worsening, others improving across generations) add new complexity to our understanding.
This study was conducted in mice, not humans, so results may not directly translate to people. The exact mechanisms by which these effects are inherited aren’t fully explained. The study doesn’t clarify whether effects are passed through genetic changes or through other mechanisms. Additionally, the study focused on specific conditions (prenatal male hormones plus high-fat diet) and may not apply to other combinations of stressors. The sample sizes for each group aren’t specified in the abstract, which makes it harder to assess statistical power.
The Bottom Line
Based on this research, maintaining a healthy diet and avoiding excessive hormonal exposure during pregnancy appears important for reproductive health across generations. However, these are animal studies, and specific recommendations for humans should come from human research and healthcare providers. The evidence suggests that pregnancy and early-life diet matter significantly, but more human studies are needed before making specific clinical recommendations. Confidence level: Moderate for the general principle that prenatal environment matters; Low for specific human applications.
This research is most relevant to women planning pregnancy, pregnant women, and healthcare providers who care for them. It’s also relevant to anyone interested in how family health history develops and why reproductive problems sometimes run in families. Men should also care because the research shows effects on male fertility across generations. This research is less immediately relevant to people not planning to have children, though the broader implications about diet and health still apply.
In the animal model, effects appeared at different times across generations—some in the first generation, others not until the third generation. In humans, if similar patterns exist, effects might take years or even decades to fully appear. Improvements from dietary changes would likely take months to years to show effects on fertility.
Want to Apply This Research?
- Track menstrual cycle regularity and length (for women) or sperm health markers if available through medical testing. Also track diet quality, specifically monitoring intake of high-fat foods and processed foods versus whole foods. For those planning pregnancy, track these metrics for 3-6 months to establish baseline patterns.
- Reduce high-fat and processed food intake, especially if planning pregnancy or already pregnant. Focus on adding more whole foods, vegetables, and lean proteins. Users can log daily meals and get feedback on fat content and overall diet quality. Set specific goals like reducing fried foods or sugary items by a certain percentage.
- For long-term tracking, monitor reproductive health markers monthly (menstrual regularity, fertility signs if applicable). Track diet quality weekly through food logging. For those who conceive, continue monitoring diet quality throughout pregnancy and postpartum. Consider annual check-ins with healthcare providers to assess reproductive health trends, especially if family history of PCOS or fertility issues exists.
This research was conducted in laboratory mice and has not been tested in humans. The findings suggest associations but do not prove cause-and-effect in people. This information is for educational purposes only and should not replace professional medical advice. If you have concerns about fertility, PCOS, or reproductive health, please consult with a qualified healthcare provider. Women who are pregnant or planning to become pregnant should discuss diet and lifestyle with their doctor. This research is preliminary and should not be used to make major health decisions without consulting medical professionals.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.